C++ error LNK2019: unresolved external symbol _main referenced in function _tmainCRTStartup -

i complete beginner c++. trying debug code because sure there pointer errors , such still trying understand can't compile it. code java program wrote song class compare methods , have transcribed c++ try , learn differences between languages, code showing no errors can't compile without error popping up. have tried looking @ solutions error have found nothing works here code win32 console project. thank help.

     // consoleapplication4.cpp : defines entry point console application. //  #include "stdafx.h" #include <string> #include <iostream>  using namespace std;  class song  { private:     string artist;     string title;     string lyrics; public:     static int sortcount;     static int searchcount;      song(string a_artist, string t_title, string l_lyrics) {          artist = a_artist;         title = t_title;         lyrics = l_lyrics;     }      //compares artist of 1 song another.      class artistcomparator {      public:         int compare(song *o1, song *o2) {             string artist1 = (*o1).artist;             string artist2 = (*o2).artist;             searchcount++;              if (artist1.compare(artist2) == 0){                 return 0;             }             searchcount++;             return (*o1).artist.compare((*o2).artist);         }      };      //compares title of 1 song another.     class titlecomparator {      public:          int compare(song arg0, song arg1) {              string title1 = arg0.title;             string title2 = arg1.title;             return title1.compare(title2);         }     };   public:      //testing method make sure song class works ,      //the compareto method works.     int main(int argc, char** argv){         song test1 = song("cat", "bat", "this not real song");         song test2 = song("cat", "apple", "also not real song");         int compareresult = test1.compareto(test2);         if (compareresult == -1){             std::cout << "test1 comes first";         }         else{             cout << "test2 comes first";             cout << test2.tostring();         }      };      string getartist(){         return artist;     };      string gettitle(){         return title;     };      string getlyrics(){         return lyrics;     };      string tostring(){         return artist + ", " + title + ", " + lyrics;     };      //compareto method used sorting songs.     //increments sortcount each time called keep track     //of efficiency of sort algorithm. private:     int compareto(song other){         sortcount++;         int art = artist.compare(other.artist);         if (art == 0){              return title.compare(other.title);         }         else             return art;     } }; 

#include "stdafx.h" #include <string> #include <iostream>  using namespace std;  class song  { private:     string artist;     string title;     string lyrics; public:     int sortcount;     static int searchcount;      song(string a_artist, string t_title, string l_lyrics) {          artist = a_artist;         title = t_title;         lyrics = l_lyrics;     }      //compares artist of 1 song another.      class artistcomparator {      public:         int compare(song *o1, song *o2) {             string artist1 = (*o1).artist;             string artist2 = (*o2).artist;             searchcount++;              if (artist1.compare(artist2) == 0){                 return 0;             }             searchcount++;             return (*o1).artist.compare((*o2).artist);         }      };      //compares title of 1 song another.     class titlecomparator {      public:          int compare(song arg0, song arg1) {              string title1 = arg0.title;             string title2 = arg1.title;             return title1.compare(title2);         }     };   public:      //testing method make sure song class works ,      //the compareto method works.       string getartist(){         return artist;     };      string gettitle(){         return title;     };      string getlyrics(){         return lyrics;     };      string tostring(){         return artist + ", " + title + ", " + lyrics;     };      //compareto method used sorting songs.     //increments sortcount each time called keep track     //of efficiency of sort algorithm.     int compareto(song other){         sortcount++;         int art = artist.compare(other.artist);         if (art == 0){              return title.compare(other.title);         }         else             return art;     } };  int main(int argc, char** argv){     song test1 = song("cat", "bat", "this not real song");     song test2 = song("cat", "apple", "also not real song");     int compareresult = test1.compareto(test2);     if (compareresult == -1){         std::cout << "test1 comes first";     }     else{         cout << "test2 comes first";         cout << test2.tostring();     }     getchar();     return 0; } 

changes done:

1. moved main() outside class
2. made compareto() function public being directly called
3. removed static int sortcount, not update variable without that.